How this heart rate zone calculator works
Your heart rate zones are five bands between your resting and max heart rate. This calculator places them using your heart rate reserve, the gap between those two numbers. It's called the Karvonen method:
Zone heart rate = resting heart rate + (max heart rate − resting heart rate) × intensity
Each zone covers a tenth of your reserve, starting at 50%:
| Zone | Name | Heart rate reserve | How it feels |
|---|---|---|---|
| Zone 1 | Recovery | 50–60% | Very easy. Warm-ups, cool-downs, and recovery days |
| Zone 2 | Easy | 60–70% | Easy. You can still talk in full sentences |
| Zone 3 | Moderate | 70–80% | Steady. You can talk in short sentences |
| Zone 4 | Hard | 80–90% | Hard. A few words at a time |
| Zone 5 | Max | 90–100% | All-out. You can only hold it briefly |
Leave a field blank and the calculator fills it in: 60 bpm for resting heart rate, and 220 − age for max heart rate. Your own numbers give you better zones.
Heart rate reserve adjusts for fitness. Take two 40-year-olds with the same estimated max of 180. With a resting heart rate of 50, Zone 2 is 128–140 bpm. With a resting heart rate of 75, it's 138–148 bpm.
Zone 2 heart rate by age
This chart uses 220 − age for max heart rate. The heart rate reserve column assumes a resting heart rate of 60, and matches the calculator and the Ness app. The % of max column uses 60–70% of max heart rate, which many charts and some watches use instead.
| Age | Max heart rate | Zone 2, heart rate reserve | Zone 2, % of max |
|---|---|---|---|
| 20 | 200 | 144–157 | 120–139 |
| 25 | 195 | 141–154 | 117–136 |
| 30 | 190 | 138–150 | 114–132 |
| 35 | 185 | 135–147 | 111–129 |
| 40 | 180 | 132–143 | 108–125 |
| 45 | 175 | 129–140 | 105–122 |
| 50 | 170 | 126–136 | 102–118 |
| 55 | 165 | 123–133 | 99–115 |
| 60 | 160 | 120–129 | 96–111 |
| 65 | 155 | 117–126 | 93–108 |
| 70 | 150 | 114–122 | 90–104 |
| 75 | 145 | 111–119 | 87–101 |
| 80 | 140 | 108–115 | 84–97 |
Enter your own resting heart rate above to get your exact range.
How to find your max heart rate
220 − age is an average across many people, not a measurement of you. Real max heart rates often land 10 or more beats above or below it. Formulas fitted to larger groups do a little better, such as 208 − 0.7 × age, and 206 − 0.88 × age for women. They're still averages.
Your Apple Watch may already have a better number. In the Health app, open Heart Rate, tap Y, and look at the top of the range. Use a reading from a hard effort, such as the end of a race or a hill sprint. Skip a spike that doesn't match what you were doing, since a loose band can misread.
If you're new to hard exercise or have a heart condition, don't go all-out just to find your max. Check with your doctor first.
Where to find your numbers in Apple Health
- Resting heart rate: search for Resting Heart Rate in the Health app. Tap M for the past month and use the average.
- Max heart rate: search for Heart Rate, tap Y, and use the highest reading from a hard workout.
Apple Watch heart rate zones vs this calculator
Apple Watch shows five heart rate zones during cardio workouts and works them out from your health data. To see yours, open the Watch app on your iPhone and go to Workout, then Heart Rate Zones. You can also set the zones by hand there. Our guide to Apple Watch heart rate zones walks through it.
If your watch and this calculator disagree, max heart rate is the usual reason. Enter the same resting and max heart rate your watch uses, and the zones should land close together.
How much time to spend in each zone
The World Health Organization recommends 150 to 300 minutes of moderate activity a week, 75 to 150 minutes of vigorous activity, or a mix of the two.
Endurance athletes do most of their training at low intensity, often around 80% of sessions, and keep the rest hard. For most people that means plenty of Zone 1 and 2, some Zone 4 or 5, and less time drifting into Zone 3 on days meant to be easy.
Track your zones with Ness
Ness works out your zones for you from Apple Health. It uses your average resting heart rate over the past 14 days and the highest heart rate in Apple Health from the past 30 days, so your zones move as your fitness does. It adds:
- Time in each zone: for every workout, and over weeks and months.
- Strain: minutes in harder zones count for more in your daily strain score.
- A coach: ask how hard to train today, and it answers from your own Apple Health data.
Ness is an AI health coach for iPhone and Apple Watch. It also scores your sleep, recovery, and stress every day, logs meals from a photo, and answers questions about your own data.
FAQ
What is Zone 2 heart rate? Zone 2 is the second of five heart rate zones: an easy effort where you can still talk in full sentences. This calculator puts it at 60–70% of your heart rate reserve. For a 40-year-old with a resting heart rate of 60, that's 132–143 bpm.
How do I calculate my heart rate zones? Subtract your resting heart rate from your max heart rate to get your heart rate reserve. Multiply the reserve by each zone's percentages, then add your resting heart rate back. Zone 2 runs from 60% to 70% of your reserve. The calculator above does the math for you.
What is my Zone 2 heart rate by age? With 220 − age as your max and a resting heart rate of 60, Zone 2 is about 141–154 bpm at 25, 132–143 at 40, 126–136 at 50, and 120–129 at 60. Your resting heart rate shifts these, so enter yours for an exact range.
Is Zone 2 60–70% of max heart rate? It depends on the method. Some charts and watches use 60–70% of max heart rate. This calculator and Ness use 60–70% of heart rate reserve, which gives a higher range for most people. For a 40-year-old with a resting heart rate of 60, that's 132–143 bpm instead of 108–125.
Is Zone 2 the same as 180 minus age? Not quite. 180 − age is the MAF formula, a single heart rate ceiling for easy aerobic training. At 40 it gives 140 bpm, close to the top of Zone 2 here for someone with a resting heart rate of 60.
Why don't my Apple Watch zones match? Usually it's max heart rate. Your watch may use a different max than 220 − age. Enter the same resting and max heart rate your watch uses and the zones should line up closely.
How accurate is 220 minus age? It's a rough average. Many people's true max is 10 or more beats away from it. If you've seen a higher heart rate in a hard effort, use that as your max instead.
Does this calculator save my data? It runs in your browser and sends nothing anywhere. It remembers your entries on this device so you can check again later. Delete them from the fields anytime.
Related reading
- Heart Rate Zones on Apple Watch: How to Set Them and Train With Them
- What's the Difference Between Heart Rate and Resting Heart Rate?
- Strain vs Stress vs Recovery: What Each Score Actually Measures
- Biological Age Calculator
- VO2 Max Calculator
Sources
- Karvonen MJ, Kentala E, Mustala O. The effects of training on heart rate: a longitudinal study. Annales Medicinae Experimentalis et Biologiae Fenniae, 1957.
- Tanaka H, Monahan KD, Seals DR. Age-predicted maximal heart rate revisited01054-8). Journal of the American College of Cardiology, 2001.
- Gulati M, et al. Heart rate response to exercise stress testing in asymptomatic women: the St. James Women Take Heart Project. Circulation, 2010.
- Bull FC, et al. World Health Organization 2020 guidelines on physical activity and sedentary behaviour. British Journal of Sports Medicine, 2020.
- Seiler S. What is best practice for training intensity and duration distribution in endurance athletes? International Journal of Sports Physiology and Performance, 2010.
This calculator is for general wellness and education. It isn't medical advice. Talk to your doctor before starting hard exercise if you have a heart condition or other health concerns.